Packing device



Uct. 6, 1953 R. G. PlETY 2,654,433

PACKING DEVICE Filed Feb. 21. 1949 a Sheets-Sheet 1 FIGS.

INVENTOR.

R.G.P|ETY A T TORNE rs R.Cl PIET! PACKING DEVICE Oct. 6, 1953 2,554,433

Filed Feb. 21, 1949 5 Sheets-Sheet 2 FIG. 5. FIG. 4.

HVVENTOR. R.G.PIETY MKM ATTORNEKS Oct. 6, 1953 G. PIETY PACKING DEVICE 5 Sheets-Sheet 3 Filed Feb. 21. 1949 11 m c c c c 3 .lwLMmH:

FIG. Z

INVENTOR. v

Ric. PIETY BY ATTORNEYS FIG. 5.

Patented Oct. 6, 1953 PACKING DEVICE Raymond G. Piety, Bartlesville, kla.,. assignor to Phillips Petroleum Company, a corporation of Delaware Application February 21, 1949-, Serial No. 77,634:

21 Claims. 1

This invention relates to a packing device for sealing off a section or a drill hole. In another aspect, it relates to a dual flowmeter unit embodying a plurality of the novel packing devices.

Heretofore, considerable difiiculty has been experienced in isolating one section of a drill hole from another in order that flow of fluids into or out of the strata adjoining such section may be individually measured.

, It is an object of this invention to provide a packing device which effectively seals on a desired section of a drill hole.-

It is a further object of this invention to provide a dual flowmeter assembly incorporating such packing devices.

It is a still further object of this invention to provide such a device in which the scaling is effected by a number of bristles in closely packed formation which may be impregnated with a suitable compound to aid in preventing leakage of fluid in a vertical direction through the packing device.

It is a still further object of the invention to provide a collapsible packing device, the outer diameter of which is variable in accordance with changes in hole diameter.

It is a still further object to provide a device for holding the aforementioned bristles in collapsed position out of contact with the walls of the drill hole until the device is lowered to an operative position, at which time the bristles are released and spring into sealing engagement with the walls of the hole.

It is a still further object of this invention to provide a packing device which is simple in operation, of rugged construction, and economical to manufacture.

Various other objects, advantages and features of the invention will become apparent from the following description, taken in conjunction. with the accompanying drawings, in which:

Figure 1. is a vertical sectional view of a flowmeter assembly utilizing a plurality of the novel packing devices;

Figure 2 is a top view of one of the packers;

Figure 3 is a vertical sectional view of a modified form of packer;

Figure 4 isa front elevational view of a collapsible packing device, with portions of the easing broken away to show the interior construction;

I Figure 5 is a top view of the collapsible packer shown by Figure 4;

Figure 6 is a vertical sectional view,- partially in elevation, of a packing device in which the bristles may be. retained in a collapsed position from which they are releasable by operation of. a latching device; and

Figure 7 is a vertical sectional view of av modined form of latching device for use with the structure of Figure 6.

Referring now to the drawings in detail, and particularly to Figure l, I have shown a flowmeter pipe assembly l0 comprising a pipe I l positioned vertically in a drill hole l2 which is ordinarily filled with fluid, such as water or mud. A pair of packing devices l4, I5 are mounted in vertically spaced position upon the pipe assembly 40. A flowmeter i6 is carried by the pipe assembly, this flowmeter being located between the packers l4, l5 and a flowmeter i1 is supported by the pipe assembly below the lower packer i5. The flowmeter i6 is carried by a pipe IQ of en.- larged cross section which is mounted concentrically with pipe I I, this pipe [9 carrying. an annular plate 20 having a circumferential flange 2! depending therefrom. An outer set of hot thermocouple junctions 22 and an inner set of cold thermocouple junctions 23 are carried by the plate 20, each set comprising a number of junctions arranged in generally circular formation about the plate. An annular heating element 24 is supported from the plate by pins 25 and 26, this element being located between the two sets 22, 23 of thermocouple junctions. A plate 28- is mounted at the lower end of pipe [9 and this plate has an upstanding flanged portion 29 which is closely spaced to the heater element 24. The lower end of pipe [9 is provided with perforations 30 so that liquid injected into the well may pass through said perforations, the interspace between flange 29 and pipe i9, and the interspace between flange 29 and flange 2 I to the drill hole. Flow of liquid in this manner produces a temperature differential betweenv the two sets of thermocouple junctions which is proportional to the rate of flow of liquid therebetween, due to the interposition of heating element 24, so that the electrical voltage produced by the thermocouple junctions as a result of this temperature differential is a direct indication of flow rate. The flowmeter may also be used to measure flow from the bore hole formation into pipe ill by interchanging the hot and cold thermocouple junctions. The lower flowmeter I! is of similar construction to flowmeter [6 except that certain parts are of smaller diameter to permit mounting of the flowmeter on the relatively small inner pipe H.

The operation of the flowmeters just described as well as the improved results obtainable by the use of two fiowmeters is set forth in my pending application, Serial No. 105,295, filed July 18, 1949, entitled Flowmeter.

The function of the packing devices l4, I5 is to seal off the region of the drill hole therebetween so that the flow of liquid into or out of this particular region may be independently determined apart from the flow at other regions of the drill hole. In order that accurate results may be obtained, the packing devices must provide an eifective seal with the drill hole walls despite substantial variations in hole diameter resulting, for example, from caving. I have found that this function is efliciently performed by the novel packers now to be described.

It will be noted that packers I4, I 5 are of generally similar construction and that each includes an annular metal plate 3| or 32 having its inner edge brazed or otherwise secured in sealing engagement with one of the pipes II and 19. An annular member 33 of resilient material, such as rubber, is secured to the other surface of each of the plates 3!, 32 and bristles 34 are, in turn, attached to the outer surface of each annular member 33. These bristles are arranged in closely packed formation and they are, in general, longer than the distance between the outer edge of the resilient member 33 and the walls of the drill hole.

Sealing of the packer is effected by adhesion of the bristles to the bore hole walls produced by wetting of the bristles by the fluid in the well, and by mutual adhesion between the bristles. In many cases, this adhesion provides a sufficient seal as to prevent appreciable leakage of fluid in "a vertical direction through the packing device. 'In other cases, however, I have found it highly advantageous to impregnate the bristles with a material, such as grease, to aid in preventing such leakage. As the flowmeter is moved upwardly or downwardly in the hole at various stages of the permeability or other survey to be made, the

bristles trail behind the packing device and remain in contact with the drill hole walls. Since 'a large number of closely packed bristles are provided, the outer ends thereof readily accommodate themselves to the contour of the drill hole and provide an eflicient sealing action at Whatever location in the hole the survey is to be conducted. Although I prefer to use nylon bristles, other materials, such as stainless steel wires and hair are suitable.

A modified form of packing device is shown by Figure 2 in which it will be noted that a pipe 35 'has an annular resilient member 36 snugly fitted against the outer surface thereof, this member carrying closely packed bristles 31 which have their inner ends embedded in the resilient member 36, the outer ends being adapted for engagement with the dril1 hole walls. A similar structure is shown in Figure 3 including a pipe 39, an annular resilient member 40, and bristles 4|. This figure shows the manner in which the bristles adapt themselves to the changing contour of the drill hole, as well as the manner in which 'the bristles trail behind the assembly as the unit 'is moved in an upward direction, Figure 3.

In some cases, very large variations in drill hole diameter are encountered. When this condition occurs, it is advantageous to use a collapsible packer of the type shown in Figure 4. In this figure, the flowmeter assembly includes a pipe 44, a pair of collapsible packers 45 and 46, a flowmeter 41 positioned between the packers and a flowmeter 48 positioned below the lower packer 46. A separate pipe is not provided for each flowmeter, as in Figure 1. I Rather, both of the flowmeters in Figure 4 have a common inlet or outlet pipe 44.

Each of the packers 45, 46 includes a collar 49 fixed on the pipe 44 and a collar 50 which is slidably mounted on pipe 44. An upper set 5| and a lower set 52 of metal rods protrude in fan-shaped arrangement from the respective collars 49 and 50, the rods of each set being radially spaced from each other. Each set adjacent upper and lower rods is interconnected by a vertical rod 54, thereby forming a plurality of assemblies each including one rod of the upper set, one of the vertical rods, and one rod of the lower set. Each adjacent pair of rod assemblies is joined by a fold 56 of water-proof fabric so that the assembly is movable from the extended position shown to a collapsed position in which the outer diameter is substantially increased.

Each packer also includes bristles 51 which are arranged in closely packed formation, the inner ends being secured to the rods 54 and their interposed folds of fabric, the outer ends engaging the walls 53 of the drill hole. Each packer also includes a reversible pump 59 having an inlet pipe 60 communicating with the interior of the packer and an outlet pipe 6| communicating with the drill hole. When this pump is operated so as to pump liquid into the packer from the drill hole, the unit is forced to the extended position, as shown. When the pump is reversed, liquid is discharged from the packer into the drill hole and the packer is collapsed with resultant increase in the diameter of the section at 54. The bristles 5'! seal off a portion of the drill hole as described in connection with Figures 1 to 3, inclusive, while the ability of the packer to be extended and collapsed permits adjustment thereof in order to compensate for large increases or decreases in hole diameter.

In Figure 6, I have shown a device wherein the packers are retained in collapsed position as the flowmeter assembly is lowered into a drill hole,

the bristles being releasable when the apparatus reaches the bottom of the hole to permit them to spring into sealing engagement with the drill hole walls. This apparatus includes a pipe suspended vertically in the drill hole, this pipe carrying a pair of vertically spaced packers 66 and 61 of the type illustrated by Figure 3 and bearing similar reference characters. A flowmeter 68 is mounted between the packers and a flowmeter 69 is mounted below the lower packer 61. The sets of bristles 4| are adapted to fit, respectively, into dished annular members H and 12, in which fashion they are retained in collapsed position spaced from the walls of the drill hole as the flowmeter descends therein. The annular members H and 12 are carried by an assembly of three rods, two of which are shown at 13 and 14, these rods also extending downwardly to a plate 76 having a depending flange 71 which is slidably mounted on the pipe 65. The plate 16 is urged downwardly by a helical spring 78 which thereby tends to engage the annular members i I, 12 from the bristles 4|, the spring 18 being mounted between a collar 19 secured to the pipe and the flange Tl. Such downward movement of the plate is normally prevented by a latching device including a ball 86 which is received within a notch 8| in flange member H and an opening 82 in the pipe 65. A plunger 84 is mounted for slid- .ing movement within the pipe 65 and this plunger is urged by a spring 86 to the position shown in Figure 6, this spring being mounted between the plunger and a plate 81 mounted interiorly of the pipe. The plunger 84 has a groove .88 formed therein which is normally positioned below the ball 80, and a rod 89 protrudes downwardly from the plunger, this rod carrying a ball .90 at its lower end.

The bristles M are held in'the collapsed position shown by Figure 6 as the assembly is lowered into a drill hole, thereby preventing wear upon the bristles during this period in which measurements are not normally taken. When the ball 90 engages the bottom of the drill hole, the plunger 94 moves upwardly against the pressure of spring 86, thereby allowing ball 80 to slide into the notch 88. This releases plate 16 from. its latched position and enables spring 18 to-force this plate downwardly, thereby lowering annular members H, 12 and permitting the bristles M to spring into engagement with the walls ofthe drill hole. It has been found that the bristles pack around the rods l3, 14 so that noappre- 'ciable leaking occurs at this point. In some cases, however, the construction may be modified so that the rods extend through the resilient members 40 rather than through the bristles 41. The decrease in wear caused by disengaging the bristles from the walls as the flowmeter islowered into the drill hole greatly increases the life of the bristles.

A modified form of latching device is shown by Figure '7, in which parts similar to those of Figure 6 are indicated by like reference characters. In this modification, an electromagnetic tripping device is substituted for the mechanical tripping device of, Figure 6. To this end, the plunger 84 is replaced by a plunger 9| having a grooved portion 92 normally positioned below the ball 89, the plunger being urged to the position shown in Figure '7 by a spring 93 which is mounted between plunger 9| and a plug 94 at the lowerend of pipe 65. A solenoid coil 95 is mounted within the pipe and its armature 96 is connected to the plunger 9|, the solenoid being energized through leads 9'! which extend to the surface through the supporting cable of the apparatus. When the solenoid is energized, the armature 96 and plunger 9| move upwardly, thereby permitting the ball 80 to move into the slot 92. mechanism and permits downward movement of plate 16 together with release of bristles 4| in the manner described in connection with Figure 6. This tripping device has the advantage that it may be actuated at any time and at any position within the drill hole. Accordingly, when the electromagnetic device is utilized, it is not necessary that the unit be lowered to the bottom of the hole before the brushes are released. In addition, there is no danger of releasing the tripping device prematurely by engagement of the plunger with an obstruction in the drill hole or a wall thereof. I

While the invention has been described in connection with a present, preferred embodiment thereof, it is to be understood that this description is illustrative only and is. not intended to limit the invention, the scope of which is defined by the appended claims.

' Having described my invention, I claim:

1. A packing device for sealingoff a section of a drill hole comprising, in combination, an elongated pipe positioned in said drill hole, an annular member of resilient material havingits inner edge in sealing engagement with said pipe,

This releases the latchin r andbristles embedded in and extending, in a sof ficiently closely packed formation as to provide a liquid seal, from the outer edge of said resilient member for engagement with the wall of the drill hole, said bristles being wetted by well fluid to cause adhesion thereof to the drill hole walls, thereby to prevent leakage of fluid a vertical direction through the packing device.

2-. A packing device for sealing ofi ase'ctionof a drill hole comprising, in combination, an elongated pipe positioned in said drill hole, anamnular member of resilient material having its inner edge in sealing engagement with said pipe, bristles embedded in and extending in sufilciently closely packed-formation as to provide a liquid seal, from the outer edge of said resilient member for engagement with the wall of the drill hole, said bristles being longer than .the distance from said outer edge to said drill hole wall, and a com.- pound impregnating said bristles to "aid in 'pre. venting leakage of fluid in a vertical direction throughthe packing device.

3. A packing device for sealing off a section'of a drill hole comprising, in combination, an elongated pipe assembly positioned in said drill hole, an annular metal plate having its inner edge in sealing engagement with said pipe assembly, an annular resilient member secured tothe outer edge of said metal plate, and bristles embedded in and extending in closely packed formation from the outer edge of said resilient member to the walls of the drill hole, said bristles being longer than the distance from the outer'edge to said drill hole wall and being adapted for ad-' hesion to each other and to the drill hole walls when wetted by the fluid inthe drill hole, thereby to prevent leakage of fluid in a vertical direction through the packing device, and a compound impregnating said bristles to aid in preventing leakage of fluid in a vertical direction through the packing device.

4. A packing device for sealing off a section of a drill hole comprising, in combination, an elongated pipe assembly positioned in said drill hole, an annular metal plate having its inner edge in sealing engagement with said pipe assembly, an annular resilient member secured to the outer edge of said metal plate, and bristles embedded in and extending in closely packed formation from the outer edge of said resilient member to the walls of the drill hole, said bristles being longer than the distance from the outer edge to said drill hole walls and being adapted for adhesion to each other and to the drill hole walls when wetted by the fluid in the drill hole, thereby to prevent leakage of fluid in a vertical direction through the packing device.

5. A packing device for sealin off a section/of a drill hole comprising, in combination, a pipe positioned in said drill hole, a pair of packers vertically spaced on said pipe, a flowmeter positioned on said pipe between said packers, and: a second flowmeter .positioned below the lower packer, each of said packers comprising an annular resilient member being secured to said pipe in sealing relationship and bristles embedded in said resilient member and the outer ends thereof being in engagement with the walls of said drill hole, said bristles being arranged in a sufficiently closely packed formation as to substantially pre vent leakage of a liquid in a vertical direction therethrough and being longer than the distance from the outer edge of said resilient member to the drill hole wall.

6. A packing device in accordance with claim in which an impregnating compound is applied to said bristles to aid in' preventing leakage of fluid in a vertical direction through said packing device.

7. 'A packing device in accordance with claim 5 in which the means for securing the inner ends of the bristles to the pipe includes an annular metal plate having its inner edge secured to said pipe assembly, and said resilient member secured to the outer edge of said plate, the inner ends of said bristles being secured to said resilient member.

8. A packing device in accordance with claim 7 in which an impregnating compound is applied to said bristles to aid in preventing leakage of fluid in a vertical direction through said packing device.

9.'A packing device for sealing off a section of a drill hole comprising, in combination, a pipe positioned in said drill hole, a collapsible support secured to said pipe, the outer diameter of said support being larger when it is collapsed than when it is in extended position, bristles extending in closely packed formation from the outer edge of said support to the walls of the drill hole, said bristles being longer than the distance from said outer edge to said drill hole walls, and a reversible pump for injecting fluid into said support to force it to its extended position, and for withdrawing fluid from said support to cause it to move to its collapsed position.

10. A packing device for sealing oif a section of a drill hole comprising, in combination, a pipe positioned in said drill hole, a collapsible support secured to said pipe, said support including upper and lower sections each having a series of metal rods protruding in generally fan-shaped arrangement from the pipe, and a fold of waterproof fabric connected to each set of adjacent rods, bristles arranged in closely packed formation extending from the outer edgeof said collapsible support and engaging the walls of the drill hole, said bristles being longer than the distance from said outer edge to said drill hole walls, a compound impregnating said bristles to aid in preventing leakage of fluid in a vertical direction through the packing device, and a reversible pump for forcing liquid into the interior of said collapsible support and for withdrawing such liquid therefrom to cause extension and collapse of said support.

11. A packing device for sealing oil a section of a drill hole comprising, in combination, a pipe assembly positioned in said drill hole, a pair of vertically spaced packers mounted on said pipe, a flowmeter secured to said pipe between said packers, and a flowmeter secured to the pipe below the lower packer, each of said packers including a collapsible support secured to said pipe, said support including upper and lower sections each having a series of metal rods protruding in generally fan-shaped arrangement from the pipe, and a fold of water-proof fabric connected to each set of adjacent rods, bristles arranged in closely packed formation extending from the outer edge of said collapsible support and engaging the walls of the drill hole, said bristles being longer than the distance from said outer edge to said drill hole walls, a compound impregnating said bristles to aid in preventing leakage of fluid in a vertical direction through the packing device, and a reversible pump for forcing liquid into the interior of said collapsible support and for withdrawing such liquid therefrom to cause extension and collapse of said support.

, 12. A packing device for sealin off a section of a drill hole comprising, in combination, a pipe positioned in said drill hole, a pair of packers supported in vertically spaced poistion on said pipe, a flowmeter positioned between said packers, and a second flowmeter positioned below the lower packer, each of said packers including a support having an inneredge in sealing engagement with said pipe, and bristles extending from an outer edge of said support and engaging the walls of the drill hole, said bristles being longer than the distance from the outer edge to the drill hole walls and being arranged in closely packed formation, a device for holding said bristles in collapsed position adjacent said pipe including a dished annular member cooperable with each set of bristles, a series of vertical rods secured to said annular members and extending downwardly to a plate positioned below the lower flowmeter, said dished annular member and pla e being slidably mounted on said pipe, a spring urging said plate in a downward direction relative to said pipe, and a latching device for preventing downward movement of said plate, said latching device being releasable to permit downward movement of said annular members relative to said pipe, whereby the bristles are freed to spring into a position wherein their outer ends engage the walls of the drill hole. a

13. A packing device in accordance with claim 12 in which the latching device includes a depending flange on said plate positioned adjacent said pipe, a notch in said depending flange, a locking member positioned in an opening in said pipe and extending into said notch, a plunger movable vertically in said pipe, 2, spring urging said lunger in a downward direction, a notch formed in said plunger and normally positioned below said locking member, and a rod protruding downwardly from said plunger, said rod being moved in an upward direction upon engagement with the lower end of the drill hole to release said locking member and permit said plate to move in a downward direction.

14. A packing device in accordance with claim 12 in which the latching device includes a flange depending from said plate and closely spaced to the outer wall of said pipe, said flange having a notch formed therein, a locking member seated in an opening in said pipe and protruding into said notch, a plunger mounted for vertical movement in said pipe, said plunger having a notched portion normally positioned below said locking member, a spring urging said plunger in a downward direction, and a solenoid for moving said plunger in an upward direction to release said locking member and permit downward movement of said plate.

15. A packing device for sealing oil a section of a drill hole comprising, in combination, an elongated pipe assembly positioned in said drill hole comprising a pair of concentric pipes, the inner pipe protruding below the outer pipe, a flowmeter positioned at the lower end of each pipe, and a pair of vertically spaced packers, one of said packers being mounted upon the outer pipe above the flowmeters and the other packer being mounted on the protruding portion of the inner pipe intermediate the flowmeters, each packer comprising a resilient support having an inner edge in sealing engagement with said pipe, and bristles embedded in and extending from an outer edge of said supportand engaging the walls of the drill hole, said bristles being longer than the distance from said outer edge to said drill hole walls and being arranged in a sufiiciently closely packed formation that, when said bristles are wetted by well fluid to cause adhesion thereof to the drill hole walls, leakage of fluid in a vertical direction through the packing device is prevented.

16. A packing device for sealing off a section of a drill hole comprising, in combination, an elongated pipe assembly positioned in said drill hole comprising a pair of concentric pipes, the inner pipe protruding below the outer pipe, a, flowmeter positioned at the lower end of each pipe, and a pair of vertically spaced packers, one of said packers being mounted upon the outer pipe above the flowmeters and the other packer being mounted on the protruding portion of the inner pipe intermediate the flowmeters, each packer comprising an annular member of resilient material and an annular metal plate in sealing engagement with the associated pipe and said resilient member, and bristles embedded in and extending from the outer edge of said resilient member and engaging the walls of the drill hole, said bristles being longer than the distance from said outer edge to said drill hole walls and being arranged in a sufficiently closely packed formation that, when said bristles are wetted by well fluid to cause adhesion thereof to the drill hole walls, leakage of fluid in a vertical direction through the packing device is prevented.

17. A packing device for sealing ofi a section of a drill hole comprising, in combination, a flowmeter, a clylindrical casing forming a part of said flowmeter, means for supporting said flowmeter and casing in a drill hole, bristles extending in a sufliciently closely packed arrangement as to provide a seal from a region spaced from said casing to the outer walls of said drill hole, said bristles being longer than the distance from said region to said drill hole walls, and means for connecting the inner ends of said bristles to said casing.

18. A packing device for sealing off a section of a drill hole comprising, in combination, a flowmeter, a cylindrical casing forming a part of said flowmeter, means for suspending said flowmeter and casing in a drill hole, bristles extending in a sufficiently closely packed arrangement as to provide a seal from a region spaced from said casing to the outer walls of said drill hole, said bristles being longer than the distance from said region to said drill hole walls, means for connecting the inner ends of said bristles to said casing, and a compound impregnating said bristles to aid in preventing leakage of fluid in a vertical direction through said packing device.

19. A packing device for sealing 011 a section of a drill hole comprising, in combination, a flowmeter, a cylindrical casing forming a part of said flowmeter, means for supporting said flowmeter and casing in a drill hole, a resilient support having an inner edge in sealing engagement with said casing, and bristles embedded in and. extending from an outer edge of said support and engaging the walls of the drill hole, said bristles being longer than the distance from said outer edge to said drill hole walls and being arranged in a sufficiently closely packed formation that, when said bristles are wetted by well fluid to cause adhesion thereof to the drill hole walls, leakage of fluid in a vertical direction through the packing device is prevented.

20. A packing device for sealing off a section of a drill hole comprising, in combination, a flowmeter, a cylindrical casing forming a part of said flowmeter, means for supporting said flowmeter and casing in a drill hole, a resilient support having an inner edge in sealing engagement with said casing, bristles embedded in and extending from an outer edge of said support and engaging the walls of the drill hole, said bristles being longer than the distance from said outer edge to said drill hole walls and being arranged in a sufliciently closely packed formation that, when said bristles are wetted by well fluid to cause adhesion thereof to the drill hole walls, leakage of fluid in a vertical direction through the packing device is prevented, and a compound impregnating said bristles to aid in preventing such leakage.

21. A packing device for sealing oif a section of a drill hole comprising, in combination, an elongated pipe assembly positioned in said drill hole comprising a pair of concentric pipes, the inner pipe protruding below the outer pipe, a. flowmeter positioned at the lower end of each said pipe, and a pair of vertically spaced packers affixed to said pipe assembly in sealing relationship so as to close a chamber portion open to said pipe assembly only through the uppermost of said flowmeters, each packer comprising a support in sealing engagement with said pipe, and bristles having their inner ends embedded in said support and extending therefrom to engage the walls of said drill hole, said bristles being longer than the distance from the outer edge to said drill hole walls and being arranged in a sufl'iciently closely packed formation that, when said bristles are wetted by well fluid to cause adhesion thereof to the drill hole walls, leakage of fluid in a vertical direction through the packing device is preven ed.

RAYMOND G. PIE'I'Y.

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